First responders found Smith unconscious in the minivan, but she was able to communicate a bit with detectives after she was revived with Narcan. (Source: Gray Television)

November 3, 2019 at 5:20 AM EST - Updated November 4 at 9:37 AM

DELAND, Fla. (WESH/CNN) - Three children, ages 1, 7 and 12, have been placed in the custody of their grandmother after police say their mother overdosed on heroin while driving her minivan on a Florida interstate.

Officials with the Volusia County Sheriff’s Office responded to a 911 call from a 12-year-old girl Thursday night. The girl and her two younger siblings were in the car with their mother, 28-year-old Tiffany Smith, when the woman allegedly passed out.

First responders found Smith unconscious in the minivan, but she was able to communicate a bit with detectives after she was revived with Narcan. Smith allegedly told investigators she was driving the children to her sister’s home in South Carolina.

Before getting on the road, Smith’s back was hurting, and detectives allege she stopped to get some heroin for the pain. A short while later, Smith was incapacitated. She pulled over and fell unresponsive.

The children were not injured. They are now in the custody of their grandmother. Two dogs in the minivan were turned over to Volusia County Animal Control officers.